1. Field of Invention
The present invention relates in general to electric door lock devices of motor vehicles, and more particularly to the electric door lock devices of a type that comprises a closure mechanism that, upon sensing a half-lock condition of a lock device of the door, forces the lock device to take a full-lock position bringing the door to its full-closed locked position and an opening mechanism that, upon need of opening the door, cancels the locked engagement between a latch plate and a striker of the lock device.
2. Description of Related Art
Hitherto, various electric door lock devices of the above-mentioned type have been proposed and put into practical use particularly in the field of wheeled motor vehicles having a hatch back type door. One of them is disclosed in Japanese Patent Second Provisional Publication (Tokkohei) 5-27748. The device disclosed by this publication comprises a lock device that includes a latch plate engageable with a striker and a locking plate engageable with the latch plate to lock the same, and a drive device that includes a moving member movable in opposite directions from a neutral position with the aid of power produced by a reversible electric motor. That is, when moved in one direction, the moving member cancels a locked engagement between the latch plate and locking plate, and when moved in the other direction, the moving member moves the latch plate from a half-latch position to a full-latch position.
However, even the electric door lock device proposed by the publication has a shortcoming due to its inherent construction. That is, when the back door is subjected to a complicated handling during its closing movement, the back door fails to have a full closed and locked position.
Accordingly, an object of the present invention is provide an electric door lock device which can assuredly induce a full closed and locked position of the back door even when the door is subjected to a complicated handling during its closing movement.
According to a first aspect of the present invention, there is provided an electric door lock device which comprises a lock device including a latch plate engageable with a striker and a locking plate engageable with the latch plate to lock the same; a drive device including a reversible electric motor, a moving member driven by the electric motor, and a half-latch switch capable of sensing a half-latch position of the latch plate relative to the locking plate, the half-latch switch being arranged to issue a half-latch representing signal when the latch plate is about to take the half-latch position during a movement thereof that is induced when the door is being closed; a closure mechanism which, upon sensing of the half-latch position by the half-latch switch, induces rotation of the electric motor in a normal direction to move the moving member from a neutral position thereby moving the latch plate to a full-latch position relative to the locking plate, and upon arrival of the moving member at a reverse rotation position, induces rotation of the electric motor in a reversed direction thereby to return the moving member to the neutral position and stops rotation of the electric motor; and a control unit which is configured to carry out a given controlling of the electric motor when a given operation is carried out, the given operation being an operation wherein under operation of the closure mechanism, the door is moved in a close direction passing through an operative position of the half-latch switch and then moved back in an open direction at a position just before the half-latch position, the given controlling being so made that when the moving member takes a position other than the neutral position upon completion of the given operation, the electric motor is rotated in a reversed direction to move the moving member to the neutral position, and when the moving member takes the neutral position upon completion of the given operation, the electric motor is stopped to keep the moving member at the neutral position.
According to a second aspect of the present invention, there is provided an electric door lock device which comprises a lock device including a latch plate engageable with a striker and a locking plate engageable with the latch plate to lock the same; a drive device including a reversible electric motor, a moving member driven by the electric motor, and a half-latch switch capable of sensing a half-latch position of the latch plate relative to the locking plate, the half-latch switch being arranged to issue a half-latch representing signal when the latch plate is about to take the half-latch position during a movement thereof that is induced when the door is being closed; a closure mechanism which, upon sensing of the half-latch position by the half-latch switch, induces rotation of the electric motor in a normal direction to move the moving member from a neutral position thereby moving the latch plate to a full-latch position relative to the locking plate, and upon arrival of the moving member at a reverse rotation position, induces rotation of the electric motor in a reversed direction thereby to return the moving member to the neutral position and stops rotation of the electric motor; an opening mechanism which, upon sensing manipulation of a handle, induces rotation of the electric motor in a reversed direction to move the moving member from the neutral position in a direction to cancel a locked engagement between the latch plate and the locking plate and upon arrival of the moving member at the reversed rotation position, induces rotation of the electric motor in a normal direction to return the moving member to the neutral position and stops rotation of the electric motor; a cam possessed by the moving member; a close detecting switch engageable with the cam; an open detecting switch engageable with the cam; and a control unit which is configured to carry out a given controlling of the electric motor when a given operation is carried out, the given operation being an operation wherein under operation of the closure mechanism, the door is moved in a close direction passing through an operative position of the half-latch switch and then moved back in an open direction at a position just before the half-latch position, the given controlling being so made that when the moving member takes a position other than the neutral position upon completion of the given operation, the electric motor is rotated in a reversed direction to move the moving member to the neutral position, and when the moving member takes the neutral position upon completion of the given operation, the electric motor is stopped to keep the moving member at the neutral position, wherein when the close and open detecting switches assume respective operative positions, the control unit stops operation of the electric motor judging that the moving member has taken the neutral position, when the close detecting switch assumes an operative position and the open detecting switch assumes an inoperative position, the control unit continues rotation of the electric motor in a normal direction judging that the moving member has taken a first position other than the neutral position, when the close detecting switch assumes an inoperative position and the open detecting switch assumes an operative position, the control unit continues rotation of the electric motor in a reversed direction judging that the moving member has taken a second position other than the first and neutral positions and when the close and open detecting switches assume respective inoperative positions, the control unit rotates the electric motor in a reversed direction judging that the moving member has taken the reverse rotation position.